Process for dyetng materials based on
polyamedes and composithons therefor



United States Patent ()fi ice Patented Feb. 1, 1966 3,232,695 PROCESSFOR DYEENG MATERIALS BASED ON POLYAMEDES AND COMPOSTTEQNS THEREFORJean-Baptiste Robin, Lyon, and Jean Etienne Rampin,Coiionges-au-lviout-dflr, France, assignors to Societe Rhodiaceta,Paris, France, a corporation of France N Drawing. Filed Nov. 21, 1962,Ser. No. 239,356 Claims priority, appiication France, Nov. 22, 1961,879,739 7 Claims. (Cl. 8-55) This application is a continuation-in-partof application Serial No. 222,653, filed September 19, 1962, and nowabandoned. As such, this application is entitled to the priority date ofNovember 22, 1961, under U.S.C. 119 for French application Serial No.879,739.

The present invention relates to a new process for colouring materialsbased on polyamides, by means of which it is possible to obtain verylevel, intense shades of good fastness without deterioration of thematerial and to new compositions for carrying out the new process.

It is known to dye textile articles consisting of polyamides with dyesof the acid type by adding to the dyeing bath products having anioniccharacter, as also products having a slightly cationic character.Uniform dyes free from streaks are thus obtained.

It is also known to treat textile articles of polyamides in aqueousmedium at temperatures above 100 C. in the presence of a reducingproduct containing sulphur. It is possible by this method to avoidyellowing of polyamides by aqueous treatment at high temperature andthus dulling of the colours and degradation of the dyed material.

There has now been discovered, and this forms the subject of the presentinvention, a new process for dyeing polyamide materials by means ofwhich it is possible to obtain even better and hitherto unachievedresults.

The process according to the invention consists in dyeing materialsbased on polyamides, at a temperature of at least 90 C., in a bathhaving a pH between 3 and 5, in the simultaneous presence of:

(a) An anionic levelling agent and preferably a compound of the formula:R(A) R, where R and R each represents a sulphonated naphthalene orbenzene nucleus which may be the same or different, A represents one ofthe radicals CH S0 or NH, and n is an integer between 0 and 4 inclusive;

(b) A weakly cationic complexing agent and particularly polyvinylpyrrolidone or a product of condensation of ethylene oxide with along-chain fatty amine or an aromatic amine, and

(c) Thiourea or one of its N-alkylated derivatives, such as Nmonomethylthiourea.

Compositions comprising the above three ingredients are novel and formpart of the present invention. They may be alone or in mixtures withsolid or liquid inert products in solution, emulsion, or dispersion butare preferably in the form of an aqueous solution.

Particularly suitable anionic levelling agents are the sodium or otheralkali metal salts of a,a-dinaphthyl-/3,fi'- disulphonic acid, or ofa,a-dinaphthylmethane-p,B'-disulphonic acid, while the substances soldunder trade names Neovadine AN and Neolisal, and the condensationproducts of ethylene oxide and laurylamine, oleylamine and stearylamineare particularly useful cationic complexing agents.

Applicants have discovered that the combination of all the dyeingconditions hereinbefore enumerated leads to results which have hithertonever been obtained.

The invention makes it possible to produce shades which are brighter andfaster to washing than when dyeing is etfected by previously knownmethods.

Moreover, it is possible by means of the invention to avoid streakinessmore readily than when dyeing with one of the hitherto known methods,because the presence of thiourea or one of its alkyl derivatives duringthe dyeing simultaneously prevents any oxidation of the polymers to bedyed and, therefore, any degradation of the dyed material and, inaddition, prevents inequalities in dyeing which result in the formationof streaks.

This is true in the case of simple acid dyes and in the case ofmetalliferous acid dyes, and even in the case of reactive dyes of acidcharacter, which is rather remarkable.

Moreover, the results obtained by employing the process according to theinvention are achieved without difiiculty, the application of the saidprocess being simple and easy.

The dyeing with simple acid or 1:1 or 2:1 metalliferous acid dyes may becarried out in a. single step in the acid medium without first applyingan alkaline pretreatment step. It is, however, necessary for all threetypes of adjuvants hereinbefore enumerated to be present in the dyeingmedium. The operation may be carried out in a bath either between C. andC. at atmospheric pressure or under pressure between 100 C. and atemperature just below that corresponding to the commencement of thedeterioration either of the material to be dyed or of the dyestuif,which temperature may range up to C. or more. Dyeing under pressure inan autoclave substantially improves the fastness and the levelness ofthe colouration obtained. Dyeing is carried out in an acid medium at apH between 3 and 5, which is obtained by the addition of a mineral acidor of an organic acid, for example acetic acid or formic acid.

On the other hand, when applying the various reactive dyestuffs of acidcharacter an alkaline treatment, preferably at a relatively lowtemperature, is advantageous. In the case of the dyeing of textilematerials, for example, this pretreatment is carried out at atemperature between the ambient temperature, for example 20 C. and 50C., at a pH adjusted between 10 and 12. The second step or dyeingprocess may be carried out in the same bath or in a second bath, underthe conditions specified in the preceding paragraph.

'The use of a reducing agent containing sulphur in the treatment oftextile materials consisting of polyamides is known but applicants havediscovered that when thiourea or an alkyl derivative thereof is employedin traces in the dyeing medium, together with the anionic levellingagent and the cationic agent, it behaves as an anti-oxidising catalyst.Itis this catalysing function which has made it possible to obtain aquality of dyeing which could not have been foreseen from the knownproperties of certain anionic agents and certain cationic agents.

In this connection it is to be noted that the quantities of thiourea, ofanionic agent and of cationic agent to be employed in the dyeing mediumvary substantially as an inverse function of the quantity of dyestulf.For example, in the case of a dyebath for textile materials thefollowing quantities of thiourea, expressed in percentage of materialtreated, are suitable:

Dyestutf, percent: Thiourea, percent 2 0.02 1 to 2 0 03 0 5 to 1 0 04 050 05 The small quantities of thiourea necessary demonstrate that itsaction is essentially catalytic.

In addition to the aforesaid advantages, it is to be noted that thepresent process, in contradistinction to conventional methods forimproving the levelness of dyeing with acid or metalliferous dyes onpolyamide materials, does not in any way reduce the yield of the dyes onthe materials, but in the majority of cases the yield is evensubstantially improved, so that it is possible to reduce the usualdyeing times.

Finally, the presence of thiourea or an alkyl derivative thereof doesnot give rise to change in shade as is the case with other activeantioxidising or reducing agents.

The process according to the invention produces a true protective efiecton materials based on polyamides and prevents or retards degradationthereof by oxidation. In an aqueous bath at high temperature, very smallquantities of oxygen are sufiicient to produce a considerablemodification of these materials. In practice, it is very dilficult toeliminate air completely from the material to be dyed and from thedyeing medium, especially in the case of textile materials, and it hashitherto frequently happened that, for example, in the course of thedyeing of textured yarns, occluded air bubbles cause breakages inwinding or weak points in made-up materials, and in addition, producedifferences in shades on the yarns. These defects are obviated by theuse of the process according to the present invention.

The invention is illustrated by the following examples in each of whichthiourea itself is used for convenience. It may be replaced with equallygood results by an alkyl derivative such as N-monomethylthiourea.

Example I A dycbath is prepared containing, per 1500 litres of liquor,750 g. of trisodium phosphate and 500 g. of the dyestutf having theformula:

OHa-O SOaNB. I

SOaNa 100 kg. of fabric consisting of polyamide 66 continuous filamentyarn of 4.4 tex. (40 denier) l3 filaments, 200 Z turns per metre aretreated in the bath for minutes at 40 C. There are then added 0.75 l. ofglacial acetic acid, 400 g. of formic acid (80% by weight), 2.5 kg. ofthe condensation product of ethylene oxide and laurylamine, 2.5 kg. ofsodium a,a-dinaphthylmethane-,8,5- disulphonate and 50 g. of thiour'ea.Dyeing is carried out for 1 hour at 100 C., whereafter the product isrinsed in a 1000-litre bath containing 500 g. of the condensationproduct of a fatty alcohol and ethylene oxide, commercially known underthe name Sunaptol 0. After Washing and drying, the fabric has a finepale-yellow colouration which is fast to washing and completely level.The fabric has undergone no degradation.

Example 11 The procedure of Example I is followed, using a dyestuff ofthe formula:

CHs-O I O H S C; OaNa I (1H3 H2 OSOgNa.

In the second phase of the dyeing, the bath is neutralised with 750 g.of glacial acetic acid, and acidified with 400 g. of formic acid Thedyed fabric has a very fast red colouration of excellent levelness,while having retained its initial mechanical properties.

Example 111 The procedure of Example 11 is followed, by using a dyestuffof the formula:

A blue colouration is obtained of remarkable fastness. The fabricexhibits no streaky or stripy effects.

Example IV kg. of a fabric consisting of polyamide 6 continnous filamentyarns of 7.7 tex. (70 denier) 23 filaments 200 Z turns per metre aredyed in 1000 l. of Water con= taining 1 kg. of a dyestulf of theformula:

SO NB 2 kg. of sodium a,cr'-dinaphthylmethane-,6,}8'-disulphonate 2 kg.of the product commercially known under the trade name Neovadine AN,

40 g. of thiourea,

The pH of the bath is adjusted to 3 by means of acetic acid.

The fabric is dyed for 1 hour at C. and rinsed and dried.

The fabric has a very bright blue colour of excellent fastness to lightand even to very vigorous washing, and is completely level, while havingretained its good mechanical properties.

Example V Piece goods made from stable fibre yarns, each 77 tex./3 x 270Z/ S, of polyamide 11 is dyed under the same conditions as in Example1V, but replacing the 'dyestufii there employed by a dyestufi having thefollowing formula:

The fastness properties of the dyeing obtained are as good as those inExample IV.

The dyeing is a fine deep fast black having no streaks.

When polyamide materials are dyed with the same dyes as in the aboveexamples, but omitting one or more of the conditions characteristic ofthe invention, dyeings are obtained Whose shades are distinctly lessbright and considerably less level.

Example VI 100 kg. of a fabric made of polyamide 66 continuous filamentyarn is introduced into a dye bath containing 1000 l. of water to whichhas been added 2 kg. of Acid Red 211 (Colour Index Second Edition 1956,Part 1, vol. 1, page 1180), and 2.5 l. of an aqueous solution containing(a) 392 g. per litre of the condensation product of laurylamine withethylene oxide, (b) 392 g. per litre of sodium dinaphthyl methanedisulphonate and (c) 16 g. per litre of thiourea.

The pH of the bath is adjusted to 3.5 by means of glacial acetic acid.Dyeing is carried out for one hour at 130 C. whereupon the fabric isrinsed and dried. The resulting fabric is dyed in a perfectly levelshade of red and retains its initial mechanical properties.

Vie claim:

1. Process for dyeing synthetic polyamide materials, comprising dyeingthe materials in a dyebath at a temperature of at least 90 C., thedyebath having a pH of between 3 and 5 and containing (a) an anionicleveling agent having the formula R(A),,R', wherein R and R eachrepresent a sulphonated aromatic nucleus selected from the groupconsisting of benzene and naphthalene nuclei, A is a divalent radicalselected from the group consisting of CH SO and NH, and n is an integerbetween 0 and 4 inclusive,

(b) a weekly cationic complexing agent selected from the groupconsisting of polyvinyl pyrrolidone, condensation products of ethyleneoxide with long chain fatty amines and condensation products of ethyleneoxide with aromatic amines,

(c) a catalytic amount of a substance selected from the group consistingof thiourea and N-alkylated thioureas (d) an anionic dyestufi.

2. Process for dyeing synthetic polyamide materials comprising firstpretreating the materials in an alkaline bath of pH between and 12 at atemperature of 50 C.

6 at most and then dyeing the materials in a dyebath at a temperature ofat least C., the dyebath having a pH of between 3 and 5 and containing(a) an anionic levelling agent having the formula R(A), R', where R andR each represent a sulphonated aromatic nucleus selected from the groupconsisting of benzene and naphthalene nuclei, A is a divalent radicalselected from the group consisting of CH SO and NH-, and n is an integerbetween 0 and 4 inclusive,

(b) a weekly cationic complexing agent selected from the groupconsisting of polyvinyl pyrrolidone, condensation products of ethyleneoxide with long chain fatty amines and condensation products of ethyleneoxide with aromatic amines,

(c) a catalytic amount of a substance selected from the group consistingof thiourea and N-alkylated thioureas (d) an anionic dyestuff.

3. Process for dyeing synthetic polyamide materials, comprising dyeingthem at a temperature above 90 C. in a dyebath having a pH between 3 and5 and containing an acid dyestuff, an alkali metal salt ofa,a-dinaphthylmethane-[3,/3'-disulphonic acid, thiourea and condensationproduct of ethylene oxide and an amide selected from the groupconsisting of laurylami-ne, oleylamine and stearylamine.

4. Process according to claim 3, wherein dyeing is preceded by atreatment of the material in an alkaline bath of pH between 10 and 12 ata temperature up to 50 C.

5. Process according to claim 6, wherein the anonic dyestuff is presentboth in the alkaline pretreatment bath and in the acid dyebath.

6. Process for dyeing synthetic polyamide materials, comprising firsttreating the materials in an alkaline bath at pH between 10 and 12 to atemperature up to 50 C. and thereafter adding to the bath (a) an anionicleveling agent having the formula R(A) R, wherein R and R each representa sulphonated aromatic nucleus selected from the group consisting ofbenzene and naphthalenev nuclei, A is a divalent radical selected fromthe group consisting of CH SO and NH, and n is an integer between 0 and4 inclusive,

(b) a Weekly cationic complexing agent selected from the groupconsisting of polyvinyl pyrrolidone, condensation products of ethyleneoxide with long chain fatty amines and condensation products of ethyleneoxide with aromatic amines,

(c) a catalytic amount of a substance selected from the group consistingof thiourea and N-alkylated thioureas,

(d) an anionic d-yestuff.

7. Composition of matter for use in dyeing synthetic polyamide articlesin level shades with anionic dyestuffs, comprising in combination,

(a) an anionic levelling agent having the formula R(A),,R, wherein R andR each represent a sulphonated aromatic nucleus selected from the groupconsisting of benzene and naphthalene nuclei, A is a divalent radicalselected from the group consisting of CH SO and -NH, and n is an integerbetween 0 and 4 inclusive,

(b) a weekly cationic complexing agent selected from the groupconsisting of polyvinyl pyrrolidone, condensation products of ethyleneoxide with long chain fatty amines and condensation products of ethyleneoxide with aromatic amines,

(c) a catalytic amount of a substance selected from the group consistingof thiourea and N-alkylated thioureas.

(References on following page) UNITED References Cited by the Examiner 72,952,506 9/1960 Dellis.

STATES PATENTS ,97 ,8 /1961 MOXaH 8-85 Munz 3 34 X OTHER REFERENCESBerthold 8-85 X 5 Diserens Chemical Technology of Dyeing and Paint-Kling 8-84 X ing, v01. 2, pages 311-325, 338-341, pub. by Reinhold Amick8-85 Publishing Corp., 1951. Fuchs 8'84 X Holmes, American DyestufiReporter, pages 702-704. Helfenberger 8-54 McGrew, American DyestuffReporter, page 136, Mautner 8- -85 X 10 Feb. 19, 1951. Gray 8--5 Geigy XNORMAN G. TORCHIN, Przmary Exammer. Schmidt 8-85 X ABRAHAM H.WINKELSTEIN, Examiner.

1. PROCESS FOR DYEING SYNTHETIC POLYAMIDE MATERIALS, COMPRISING DYEINGTHE MATERIALS IN A DYEBATH AT A TEMPERATURE OF AT LEAST 90*C., THEDYEBATH HAVING A PH OF BETWEEN 3 AND 5 AND CONTAINING (A) AN ANIONICLEVELING AGENT HAVING THE FORMULA R(A)NR'', WHEREIN R AND R'' EACHREPRESENT A SULPHONATED AROMATIC NUCLEUS SELECTED FROM THE GROUPCONSISTING OF BENZENE AND NAPHTHALENE NUCLEI, A IS A DIVALENT RADICALSELECTED FROM THE GROUP CONSISTING OF -CH2-, SO2- AND -NH-, AND N IS ANINTEGER BETWEEN 0 AND 4 INCLUSIVE, (B) A WEEKLY CATIONIC COMPLEXINGAGENT SELECTED FROM THE GROUP CONSISTING OF POLYVINYL PYRROLIDONE,CONDENSATION PRODUCTS OF ETHYLENE OXIDE WITH LONG CHAIN FATTY AMINES ANDCONDENSATION PRODUCTS OF ETHYLENE OXIDE WITH AROMATIC AMINES, (C) ACATALYTIC AMOUNT OF A SUBSTANCE SELECTED FROM THE GROUP CONSISTING OFTHIOUREA AND N-ALKYLATED THIOUREAS (D) AN ANIONIC DYESTUFF.